Slide contactor switch



Sem 5 m5@ E. G. LODGE 252m@ SLIDE CONTACTOR SWITCH INVENTOR [0M/fvg 645m? l @paf ATTORN EYS Sept. 5 1950 E. G. LODGE 2,52L468 SLIDE CONTACTOR SWITCH Filed Sept. 12, 1946 2 Sheets-Sheet 2 47 f77/l I i-9 f i )f A r J1 7 6a 7 i- 64.*.' I .5 -ff -l 74 72 70 .f6 F 77/7.; "5

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'fm1-7- -L 6/ o o 66 f3 n. j n 45' 42 INVENTOR TEE' www@ ATTORNEYS patented sept. s, 1950 2,521,468

SLIDE CONTACTOR SWITCH Edmund Gilbert Lodge, Rosemont, Pa., assigner to John Keefe, Jr., trading as Keefe Electronic Sales Co., Camden, N. J. i

Application september 12, 1946, serial No. 696,549

17 Claims. l

The present invention relates to circuit closers, and more particularly to a novel slide contacter switch.

In switches of the slide contactor type hereto- (Cl. 20G-77) 2 peculiarly well adapted to high current D. C. operation with adequate quenching of the spark; to provide a slide switch in which the increase of current carrying capacity is practically a linear fore designed, one of which, Patent No. 2,246,373, 5 function of increase `of size of the parts; to prois a purely illustrative example, the contact areas vide a slide switch of extremely sharp and quick are approximately of pin-point magnitude so that make and break and in which the speed of the fractional deviations of cooperating parts from make and break is substantially independent oi the ideal, due to faulty manufacture, careless asthe speed of operation of the slide member; to sembly, or wear, result in poor electrical connecprovide a slide switch utilizing a roller contact tions, arclng at the contacts, and loss of energy. for bridging fixed contacts in which the speed of It is also noteworthy that large production the break is a function of the weight of the roller; switches of the prior art have been so deficient to provide a slide switch of high current-carrying in contacting area that it required large switch capacity in a physically small switch; to provide components to carry very small currents, with l5 a slide switch which is self-indexing and without a consequent high cost and appreciable size of an override; and to provide other objects and the switches. Obviously, this militated against advantages as will become more apparent as the the availability of the switches for many of the description proceeds. most common applications for switches. As a In the accompanying drawings forming part of corollary it required very large and heavy switches .20 this description: to carry larger currents, with further undue in- Fig. l represents a sectional elevation of a sin-l creases in'sizes and costs. gle pole, double throw snap switch embodying Some of the objects of the present invention one form of the present invention. are: to provide an improved snap switch for clos- Fig. 2 represents a transverse section thereing the terminals of an electric circuit; to provide through taken on line 2 2 thereof. a switch wherein contact areas are relatively Fig. 3 represents a fragmentary schematic llla'rge; to provide a switch so constructed and lustration of the successive positions and deforarranged as to materially reduce the danger of mations of the actuating spring device of the inarcing and burning away of the contacts; to provention, showing at the top figure the roller convide a switch which automatically maintains tact seated firmly on two spaced contacts, with such a pressure on the contacts as will ensure the spring substantially symmetrically disposed maximum and efficient results; to provide a switch on the axle of the roller to push same down evenly wherein a spring serves not only to bias the conagainst the contacts, the figure in the middle tactor to good electrical contact but also coacts position indicates the change of deformation of with the manual or other shifting of the slide the spring as pressure is applied endwise of the contacter to urge the contactor from one position wire to bend same to change the resultant presto another with a pronounced high velocity snap sure on the axle of the roller just prior to its action; to provide a slide switch in which with attainment of a resultant pressure line causing mere variations in sizes of parts, currents of the roller to snap from the said two contacts and practically any given magnitude can be coninto circuit-making contact with another pair of trolled; to provide a slide switch of such `simple contacts and the lower figure represents the nal construction and of such few parts that autodisposition of the roller and tlze new substantially kmatic assembly is facilitated; to provide a slide symmetrical disposition of the spring exerting switch of extreme economy of manufacturing downward pressure from the spring upon the axle costs; to provide a snap switch utilizing a roller of the roller to cause even pressure thereof against for bridging stationary contacts which automatithe said two successive electrode contacts, in a cally is caused-to rotate during use to both effect three electrode switch having a single pole and self-wiping and new contact surfaces to the fixed a double throw. contacts; to provide a slide switch of extremely Fig. 4 represents a fragmentary enlarged schelow Contact resistance; to provide a slide switch matic fragment of the spring and roller showing in which heat incident to arcing is quickly dissithe substantially symmetrical spring disposition pated to open air due both to the large area of according to the upper and lower figures of Fig. 3. the contact terminals as well as to the short Fig. 5 represents a fragmentary enlarged schelengths of such terminals extending into the enmatic. fragment of the spring and roller, showing closure of the switch; to provide a slide switch the asymmetrical disposition yof the spring and the roller as the resultant pressure on the roller progresses from that which is preponderantly vertical toward a resultant line of pressure approaching the preponderantly horizontal.

Fig. 6 represents a sectional elevation of a double pole, double throw switch according to a modified form of the invention of Fig. 1.

Fig. 7 represents a section taken on line 1'1 of Fig. 6.

Fig. 8 represents a transverse section therethrough taken on line 8--3 of Fig. '7.

Fig. 9 represents a bottom or reflected plan of the slide element of the switch of Fig. 6.

Referring to Figs. 1 and 2 of the drawings, in an illustratively simplified form of the invention, an electrode plate l of insulating material, such as of Bakelite or the like, is provided, in which a series, in this case illustratively, three electrodes or contacts II, I2, and I3 are mounted, as by staking, in evenly spaced relation in the plate. The contacts are extended a slight distance above the upper surface of the plate III in transversely elongated contacts respectively I4, I5, and IB, which are quite heavy and solid, and extend transversely of the plate for appreciable distances while providing clearance for the skirt of.

the slide element to be described. The contacts I4, I5, and I6 are in parallel relation and arranged for selective engagement by a circuit controlling roller to be described. The contacts are continued downwardly below the plate in the wiring terminals as indicated, for the attachment of such leads as may be desired. If the switch is to be a double throw, single pole switch, then the central electrode I2 will carry one side of the line current, and the outside electrodes II and I3 respectively will connect with the alternately energized circuits leading back to the other side of the line. If it is desired to provide a single throw switch between on and om the central electrode I2 will be energized as will one or the other of the electrodes II or I3, with the remaining electrode blank or out of a line circuit to form with the roller to be described an oiT' setting. It is of importance that the great mass or body of the several electrodes are below the plate IIl, and thus are outside of the switch housing to be described. The mounting of the electrodes in the stamped or otherwise formed plates II) as an automatic machine operation will be appreciated.

A roller contact I1 is provided, having an outer peripheral contact-making area I8, of such total axial extent as to be substantially coextensive with the linear extent of the contacts I4, I5, and I5. In the center the roller is turned down or otherwise provided with a thin peripheral groove 20, leading to a transverse integral connecting axle 2I. The roller diameter is such that when engaged between a pair of adjacent electrodes, illustratively I4 and I5, it is out of contact with the plate IU, and yet has such axial extent as to establish lines of contact with the respective electrodes with the only interruption being at the peripheral groove. The roller is mounted to seat and self-index and self-seat itself upon alternate pairs of electrodes, either I4 and I5, or I5 and I6, and at rest is pushed substantially normally of the plate into the circuit-making engagement noted. The push is by a spring of simplified nature having a central generally arcuate portion 22, arranged to be mounted in the groove 2D and to contact the periphery of the axle portion 2 I. It is an important function of the central curved portion of the spring to elect a resilient urge on the axle and thus upon the roller, either in a generally symmetrical disposition in a direction normal to the plate III, or in a generally asymmetrical disposition in' a direction oblique to the normal, approaching the parallel to the plate I0. plished, illustratively, by providing a pair of wings 23 and 24, formed as integral prolongations of the central curved portion 22, sweeping upwardly out of the horizontal by curved corners respectively 25 and 26. In the preferred form shown in Figs. 1 and 2, the spring wings terminate in ends lying in the axial extent of the wings as shown at 21 and 28 respectively.

In order to guide and slide the spring and thus the roller relative to the stationary plate I0 and the contacts which the latter carries, it is preferred to provide a unitary insulating block I3 such, for instance, as of a molded plastic, having a lower substantially planar face 3I defining the lower edge of a depending skirt 32, surrounding a central generally substantially arcuate recess 29 to house the roller I1 and provided with grooves 33 and 34, to receive the respective wings 23 and 24, with clearance between the respective ends 21 and 28 of the latter and the inner end surfaces 35 and 36 of the skirt 32. 'I'he block terminates in an actuating knob extension 31 of generally rectangular cross section.

A housing or casing is provided, preferablyA -plate of the housing has an aperture 43 in which the rectangular knob 31 of the sliding element is disposed, when the upper surface of the block Il is in slidably guided relation to the inner surface of the plate. The lateral surfaces of the block 30 are slidably guided by the respective side walls of the casing or housing formed of the open ended compartment defined by the top plate and the side walls.

It will be observed that the parts as so far described are predeterminedly shaped and organized so as to conduce toward automatic assembly. Thus, the pre-shaped housing is mounted with the open end extending vertically upward, the knob 31 is threaded downwardly through the opening 43, and the block is mounted in the case, the spring element is dropped into the grooves with the central curved portion disposed in the curved recess 32, the roller contact is dropped into the recess straddling the spring portion 22 so that the axle element of the roller contacts and physically engages the arcuate portion 22 of the spring, the pre-formed plate I0 with the mounted electrodes or contacts, and side notches 39 is dropped or forced into the space between the lugs or ears 42, with the lugs received in notches 39 and with the plate IU seating against the lower edges of the side walls 40 and 4I of the housing. This seating action thus forces .the fixed contacts to bear against the roller and to move it against the resilience of the spring to cause the roller to react against the electrode contacts, while resiliently supporting the slide element in substantially frictionless slightly spaced relation of the lower planar surface relative to the upper surface of the plate II). As a completion of the automatic assembly, the lugs or ears 42 are peened over against the lower surface of the plate I0, and the assembly is complete.

The operation of the switch is as follows: As-

This spring function is accom.

electrical engagement with the electrode contacts, the spring slides in the slide block 30 to dispose itself substantially symmetrically of the axle as indicated in that figure, although it need not at this instant be exactly symmetrical of the block 30. At this point the ends 21 and 28 of the spring wings or arms 23 and 24 are respectively more or less spaced from the abutting inner surfaces 35 and 36 of the slide member and the spring pressure line is substantially perpendicular to the plate bisecting the contacts I5 and vI6 bridged by the roller and the knob has been disposed in the slot 43 in substantial engagement with or at least adjacent to the right hand end of the slot. Assuming that this controls a given circuit through electrode contacts I5 and I6 and it is desired to reverse the switch so as to open the said circuit and to close a circuit through electrode contacts I5 and I4, the operator slides the slide member longitudinally of the housing parallel to the plate I toward the left in Fig. 3. In the course of this shift, the inner abutting surface 36 of the slide member abuts the free end 28 of the spring to which it is juxtaposed and starts to apply force substantially endwise thereof. As the line of applied force is horizontal, or substantially parallel to the plate ID, and as the' wing 24 of the spring is angularly divergent from this line of force or pressure, the curved central portion 22 of the spring is urged toward the left, progressively shifting the point of contact of the curve 22 on the.,axle 2I angularly of the axle from its initial rest point on a diameter of the i axle substantially bisecting the contacts I and I6 bridged by the roller to points on the axle on diameters angularly divergent from the said initial diameter. Up to a final point of contact, owing to the seating of the roller between the contact electrodes I6 and I5 the roller resists shifting motion. The continuation of the endwise pressure on the wing 24 of the spring forces the spring to a position of asymmetryin which the curved connection 26 between the wing 24 and the curved central portion 22 moves downwardly toward the plate I0, while the other connection, the curved portion between the central curved portion 22 and the other wing 23 of the spring, moves upwardly so that a plane tangent to the curves 25 and 26 is and becomes increasingly angularly more divergent from the plane of the plate I0. This action causes the curved central portion 22 of the spring with deformation to move its point of engagement with the axle still closer to the plate I0 on a diameter of the axle and roller which is progressively more acutely angularly divergent from the plate I0 with an yangularly shifting resultant pressure along that line. This progressively shifting resultant is composed of a diminishing vertical pressure on the roller and an increasing and ultimately a preponderating pressure longitudinally of the casing, parallel to the plate I Il. At some point in the developing shift of pressures the preponderance of pressure longitudinally of the plate forces the axle and thus the roller longitudinally of the plate, causing the roller to break lts engagement with the contact electrode I6, and to snap very quickly cross the central electrode contact, during which it must either wipe on o1' turn somewhat about the central electrode I5. However, at this juncture the central portion 22 of the spring is so cocked that there is an effective 6 clearance between the axle and the spring portion 22 in the line of motion of the axle of the roller in moving from the crest of contact I5 at which it is out of engagement with both contacts I4 and I6 in moving to seated position of the roller on both contacts I5 and I4, which mo-y mentarily permits relatively catapulted "free flight of the roller during which it can change its relative angular position, before again becoming engaged tightly between the curve 22 of the spring and the two electrodes I4 and I5. This is an important feature as it enables the roller to progress angularly as it switches back and forth to present new contact areas to the xed electrode contacts. It also enables both a quick make as well as breakf Moreover, and of lmportance, is the fact that the spring portion 22 is intersected by the axle at the end of the free flight o f the roller, to absorb some of the kinetic energy of the roller to damp same and force it downward into seated indexed symmetrical balanced position on the contacts I4 and I5 without either bouncing or overriding. The arcuate recess 29 is also of such vertical and longitudinal dimensions as to permit this jump or propelled movement, w`hile being laterally of such relatively close configuration as to exert slightly spaced areas having guiding functions on the roller without binding same.

It will be apparent that the switch as thus described is cheap, made of few and simplified parts, and that in the enclosure formed by the sliding block or member 30 and the plate III, the amount of metal of the switch is a minimum as the roller is thus substantially completely housed, while the contacts only expose the mere terminal edge portions extending from the floor of the plate I 0. It will be understood that when the powdered sintered Alnico case is used the magnetic iiux of the highly magnetizecl case at its most intense path between the poles formed of the terminals of the side walls, which is substantially across the fixed contacts, quickly quenches the l a plurality of Separately actuatable switches in a single entity. It will also be obvious that although in the preferred form the alignment of the electrodes is in a plane, they can equally well be disposed in an arc, so that the roller axis moves in an arc, except for the deviations therefrom incident to switching, as noted, instead of in the substantial plane as described above. Further, it may be desired to cause a plurality of switches to be disposed in interlocking arrangements, such that a movement of one switch in moving toward one circuit controlling disposition is accompanied by a complemental synchronous movement of another switch toward unswltching or other changes of circuits.

Furthermore, the principles involved can be used to excellent advantage in plural circuit controls, as indicated in Figs. 6 to 9 inclusive. Thus, referring to these figures, the plate 45 is provided with one set of electrode contacts respectively 46, y4'I, and 48 extending in spaced series along one side of the plate 45, and in spaced relation ing the other face of the groove 51. The spring as previously described may be used to embrace and control the roller as in the earlier figures, although if desired a further modification may be made as shown in Fig. 6. In this case, the sliding insulating member for the switch 6| is provided with the lower peripheral skirt 62, surrounding the central arcuate recess B3, and leading by the grooves respectively 64 and 65 to the recesses or apertures 66 and 61 formed in the i block. These latter are preferably of such longitudinal extent as to have clearance in both directions from the bent terminal ends of the spring to be described, although excellent results attach to having the recesses just large enough to receive said ends of the springs. 'I'he spring for actuating the roller has the similar central curved portion 68 merging by the curves 1l and 1l into the oppositely extending upwardly inclined wings 12 and 13 having the angularly divergent ends respectively 14 and 15, which seat loosely or tightly in the recesses 66 and $1. 'I'he block has the control or actuating knob 16. The housing 11 is similar to that already described, having the recess 18. The roller functions as before except that the roller component parts forming the circuit controlling members are relatively insulated from each other and from the spring, and the switch in its actuation simultaneously controls circuits between electrodes 5I and 52 on one half, and 41 and 48 on the other, and in alternation thereto, simultaneously controls circuits between contacts 5| and 50 on one side and 41 and 45 on the other. The possibility of additional sets of rollers and contacts for additional circuits will be understood, and the compactness of such single switch for the control of pluralities of sets of electrodes will also be understood.

The advantages, simplicity, and extremely low cost of the switch will be apparent.

Having thus described my invention, I claim:

l. A slide switch comprising a housing, a slide member in the housing and having a restricted travel longitudinally of the housing, said slide member having a lower recess, said slide member also having a spring element receiving groove, a plurality of contacts disposed transversely in the housing in mutually spaced relation longitudinally of the housing, a substantially symmetrical spring element mounted in the groove and having a curved portion extending into the recess, a roller element comprising two roller surfaces connected by an axial portion of reduced diameter compared to the roller surfaces and arranged for movement in the recess, said roller element arranged to bridge selected pairs of contacts and to establish lines of contact therewith in response to pressure from the curved portion of the spring element engaging the axial portion of the roller, means for transmitting thrust to the spring element longitudinally of the housing to develop longitudinal pressure on the roller to cause it to snap from. one bridging re- 8 lation .with one pair of contacts to bridging relation to another pair of contacts in response to longitudinal sliding movement of the slide member. l

2. A slide switch comprising a roller having a pair of spaced roller elements connected by an axle, a spring element including a substanally central portion formed in a substantial arc, means mounting the spring element so that the substantial arc thereof is disposed between the roller elements in contact with the said axle, contacts bridged by the roller elements, said means for mounting the spring element arranged in shift it in a path transverse of the roller and of the contacts, said spring element arranged duringthe shift to change its point of bearing on the axle from a normal position urging the roller elements in a direction generally bisecting the contacts with which the roller is in contact to a pointof bearing generally transverse of the contacts to snap the roller from its pomtion bridging a pair of contacts.

3. A switch comprising a support, two contacts on the support in spaced relation extending above the surface of the support, said contacts being in substantially parallel spaced relation, a roller having a cylindrical contour and arranged to seat upon the parallel contacts with a portion of its periphery below the level of the said contacts, said roller having a peripheral groove, a spring engaging the roller in the groove, said spring having a portion curved to enter the groove and having reentrantly bent wings the ends of which are in a plane above the juncture of said wings with the curved portion, and means imposing endwise pressure oma wing to deform the curved portion of the spring to exert a resultant thrust on the roller having a component preponderantly transverse to the axis 0f the roller and of the two contacts to force the roller from the engagement with the said contacts.

4. A switch comprising an insulating support, a plurality of spaced contacts mounted upon and extending above the said support in parallel spaced relation, a roller contact having a peripheral groove defining an axle and arranged to seat upon said spaced contacts with an arcuate portion of the roller extending downwardly below the fixed contacts out of contact with the said insulating base, a spring having a central portion disposed in the groove, engaging the axle and merging into integral extensions, means for exerting compressing pressure on one of said extensions to deform the central portion to change an initial downward pressure on the axle into a pressure transverse of the axle and of the contacts to move the roller as a function of deformation of said spring.

5. A slide switch comprising an insulating support, a pair of contacts mounted on and extending above said support in spaced relation, e, second pair of contacts mounted on the support in spaced relation, the contacts of one pair being in aligned spaced relation to the contacts of the other pair, a rollei comprising a pair of spaced metallic members of cylindrical contour and a connecting axle, means for moving the roller relative to both of said pairs of contacts, means insulating the metallic contact elements from each other and from said means, said means for moving the roller comprising a spring having angularly divergent wings and a central generally curved portion, and means for exerting deforming pressure on the spring to cause it to exert a progressively shifting pressure on the 9 axle to move the roller from the said pairs of contacts.

6. A switch comprising control means having a path of movement, means guiding the means in the path of movement, an insulating support, a .pair of contacts mounted in and extending above the support, a. roller contact, means exerting pressure on the roller to force the roller against the contacts and deformable under pressure from the control means to force the roller out of engagement with both of said contacts as the means moves on its path of movement, said pressure exerting means comprising a spring having a central generally arcuate portion and divergent Wings leading into the arcuate portion by corners both respectively substantially tangent to a common plane` which is substantially parallel to the plane of the contacts in the undeformed spring condition and which common plane is angularly inclined from the plane of the contacts in the deformed spring condition.

7. A switch comprising a movable control element, a guide housing ih which the element has guided movement, contact elements in the guide housing juxtaposed to the control element. said control element having a recess in the side toward the contact elements, a roller contact having a bearing portion, resilient means in said recess having a generally varcuate portion and disposed with said arcuate portion engaging the said bearing portion on one side of the resilient means and exerting resilient pressure thereon when at rest, and said resilient means disposed in engagement on the other side thereof by the control element, said resilient means being disposed for limited bodily shifting movements relative to the control element transverse of the contacts and being movable with said control element for changing the direction of resilient pressure on the bearing element arising from engagement of said generally arcuate portion with said bearing portion to shift the roller contact relative to said contact elements.

8. A switch comprising a guide housing including an insulating strip, a plurality of contacts mounted on the insulatingstrip and disposed in a series longitudinally of the guide housing, a roller contact having a bearing portion and arranged to bridge adjacent contacts, a movable control element mounted on the guide housing for movement longitudinal of the series of contacts, a spring biased device comprising a generally centrally disposed substantially arcuate portion between wings, said control element being contoured to house and permit limited bodily `motion of the generally arcuate portion generally to be resiliently engaged between the control element and the bearing portion of said roller with the generally arcuate portion of the spring biased device engaging said bearing portion to bias the roller toward engaging both of a pair of spaced contacts, and said spring biased device arranged to move with the control element to impart movement to the roller longitudinal of the housing to move said roller out of bridging contact with said pair of adjacent contacts through pressure from said substantially arcuate portion upon said bearing portion. v

9. A switch comprising a plurality of aligned relatively insulated contacts having appreciable length transverse of the alignment, a roller of appreciable axial extent arranged to selectively bridge pairs of adjacent contacts, a bearing elefor limiting the motion of the control element away from said contacts, an elongated spring element having a median substantially arcuate portion arranged for abutting engagement with the bearing guide of said roller contact and for sliding engagement with the control element to force the latter toward the means guiding the control element and the roller toward a pair of adjacent contacts to which it is juxtaposed, and means on the control element limiting the sliding of the spring element to cause the spring element to move with the control element longitudinally of lthe aligned contacts to force the roller out of bridging relation to said selected pair of contacts to which it is juxtaposed.

10. A switch comprising guide means, a control element mounted for guided movement relative to the guide means, a plurality of spaced contacts mounted on the guide means, a roller contact having a bearing portion and arranged to bridge adjacent contacts, spring means comprising a central substantially curved portion and wings extending in opposite directions from the curved portion, said substantially curved portion being of larger radius than said bearing portion and having an opening between the wings, said substantially curved portion disposed substantially in a plane normal to the axis of said roller and engaged between the control element and the bearing portion of said roller, and means on said control element engaging a wing on said substantially curved portion for forcing said substantially curved portion to move with said control element to move said roller.

11. A switch comprising guide means, a control element mounted for guided movement relative to said guide means in a iixed path and having abutment elements spaced longitudinally oi' said path, a plurality of contacts on said guide means spaced longitudinally of said path, a roller contact arranged to bridge a. pair of said contacts and having a bearing portion, a spring disposed generally longitudinally of said path and of predeterminedly shorter length than the distance between said abutments so as to have limited bodily shifting motion between said abutments and relative to said controlelement, said spring including a substantially median curved portion f larger than and disposed for resilient engagement with the bearing portion of said roller contact and arranged to develop a lateral component against said bearing portion of said roller when shifted through pressure from an abutment when moving with the control element to move the roller on said path out of its said bridging relation. g

' 12.v A switch comprising guide means, a plurality of aligned relatively' spaced contacts mounted on the guide means, a control element movable relative to the guide means and to the respective contacts, a roller contact having a bearing portion and disposed to selectively bridge pairs of adjacent contacts of said plurality, spring means comprising wings and an intermediate curved portion engaging said bearing portion of said roller and of such curvature as to be substantially tangential to said bearing portion with contacting areas of the spring and bearing portion of the roller disposed in a given angular relation to the axis of the roller with the parts at rest and with the roller bridging one of Said pairs of contacts, said wings slidably en- 11 gaging said control element, means on said control element' for limiting the bodily sliding movement of said spring means relative to said control element, said spring means disposed for movement with said control element and to change the angular relationship of the contacting areas of the spring means and bearing portion to the axis of the roller to force the roller transversely out of bridging relation to one said pair oi' contacts into bridging relationship to the other of said pairs, and said spring means arranged in response to movement of the roller in moving from bridging one pair of contacts to the next said pair thereof to move bodily relative to the control element to cause the substantial resumption of the iirst mentioned angular rela? tionship of the contacting areas of the curved spring portion and the bearing portion of the roller to the axis of said roller.

13. A switch comprising guide means, a control element mounted for guided movement relative to the guide means, a roller contact comprising two roller portions connected by an axle and deiining a peripheral groove, contact means on the guide means disposed for bridging by said roller portions, spring means havinlg a generally curved portion larger than the axle disposed in part at least in said groove engaging the axle substantially tangentially thereof, said generally curved portion of said spring means lying and maintained substantially in a plane parallel to the guided movement of said control element and normal to said axle, said generally curved portion of the spring means disposed for bodily shifting with and also relative to said control means and arranged at rest to exert a bias on the roller toward said contact means and when moving with the control means to exert a bias on said roller transverse of said contacts.

14. A switch comprising supporting means, a plurality of metallic members disposed on the means in substantially aligned mutually spaced relation and of which at least two are contacts, annular bridging means having a bearing portion and arranged selectively to bridge one or another pair of adjacent members, a movable control element juxtaposed to and movable generally parallel to the line of members, spring means comprising a generally C-shaped element larger than and bearing tangentially against the bearing portion of the bridging means and arranged at rest to exert a bias against said bearing portion to bias the annular means against the instantane` disposed about a diameter of the bridging element bisecting said instantaneously bridged members, and means responsive to thrust from the control element in its line of movement for distorting the C-shaped element so as to shift the tangential engagement thereof with the bearing portion angularly of the latter to effect clearance between the element and said bearing portion in said line of movement while moving the said open end thereof to asymmetry to said diameter so as to transmit a thrust to said annular bridging means in said line to move same from the instantaneous bridging relation into bridging relation to another pair of members with momentary free flight relative to the spring means.

15. A self-indexing switch comprised of a rst portion and a second portion of which one is relatively movable and one is relatively xed,

complemental means on the respective portions for guiding one portion relative to the other in a. guided path of relative movement, a plurality of linearly extending bars mounted on the nrst portion in parallel spaced relation in alignment on said path and forming a ilrst and second pair of adjacent bars of which one bar is common to both pairs, a cylindrical contactor including an axle of smaller diameter than the contactor and mounted for controlled movement relative to both portions in a plane aligned with said path normal to the respective bars, the axis of said contactor being parallel to said bars, the diameter of said contactor being greater than 'said spaced relation to provide two peripherally spaced substantial lines of contact when the contactor is disposed in tangential bridging relation to a rst pair of bars, spring biased shifting means between the second portion and said axle and comprising a device for enclosing the axle on three sides thereof, said device having internal clearances in the line of said path greater than the diameter of said axle, and means for producing relative thrust from said device against said axle in response to relative motion of the portions to force the contactor out of bridging relation with said ilrst pair ofbars and into bridging relation with the second pair of bars, said contactor being biased into self-indexed relation with said second pair of bars as the axle adjusts itself in the clearance in said device.

16. A self-indexing switch comprising a cylindrical roller contactor including an axle of smaller diameter than the cylindrical contactor, a support, a plurality of bars mounted on the support in parallel spaced relation parallel to the axis of the contactor, said spaced relation being less than the diameter of said contactor to provide line contacts respectively at opposite sides of said contactor when the contactor is mounted on a pair of adjacent bars bridging same in tangential relation to the bars, a movable housing having a recess to receive said contactor, said recess being longer than the diameter of said contactor to provide side clearances for controlled movement of said contactor, guide means on the support for guiding the movable housing for movement in a path generally transverse of said bars, and contactor shifting means comprising an open jaw straddling said axle with a lost motion connection in the line of said path whereby relative movement of said axle and jaw is provided, said shifting means further comprising biasing means reacting between the housing and said axle to urge the contactor into bridging relation with a selected pair of bars, whereby the contactor ris- 1 ing and then falling about the far bar of the pair in the path of movement of the housing moves relative to both the housing and said Jaw and is self-indexed.

17. A self-indexing switch comprising a cylindrical roller contactor including an axle of smaller diameter than the cylindrical contactor, a support, a plurality of bars mounted on the support in parallel spaced relation parallel to the axis of the contactor, said spaced relation being `less than the diameter of said contactor to provide line contacts respectively at opposite sides of said contactor when the contactor is mounted on a pair of adjacent bars bridging same in tangential relation to the bars, a movable housing having a recess to receive said contactor. said recess being longer than the diameter of said contactor to provide side clearances for controlledmovement of said oontactor, guide means jon thesupportifor guiding the movable housing vg 4for movexxneiitiin a path generally transverse of saidbars, qontacinr shitting means comprising f han open Jawsfaddling said axle with a lost mol tion connection in the line of said path whereby relative movement ot said axle and .law is prog vided. said,- means further comprising biasing me'a ,l eacting between the housing and said axle to urge the contacto:- into bridging relation with ,..selected pair of bars, and means tov foree out ot said bridgins relation with'said' pair ot bars, whereby the oontumor rising and then falling about the far bar ofthe pairfi'nfthe `path oi movement of the housing` moves relative to both the housing and said .iaw' and is :wifi-indexed,- and the Jaw adjusts itli'xited lostmotion in the housing. zu

' mMUND GILBERT MDGE.

iueopoi'ating a limited lost motion in the housing v to developthrust in the general line oi said path 14 REFERENCES CITED The following references are of record in the file oi.' this patent:

UNITED STATES PATENTS 

